1) Barrel filled with sand placed on most U.S. military ranges and specifically near the armory. Used to clear out a weapon in an unknown condition. That way if a round is discharged it enters the sand and is stopped instead of entering your platoon mate.

2) A Company or platoon whore. A uniform chaser who is used by many of the men of one unit to clear their "personal issue."

Devil 1: I can't believe they outlawed the whore house.
Devil 2: Yeah, guess I'll just have to use the company clearing barrel instead.